From fabe02ddc2e802e75fa90db003779ba961b90523 Mon Sep 17 00:00:00 2001
From: Tiago Koji Castro Shibata <ticastro@microsoft.com>
Date: Tue, 13 Oct 2020 20:10:33 -0700
Subject: [PATCH] Don't change global FPU state during round-half-to-even
 (#5376)

* Don't change global FPU state

* Handle infinity properly
---
 onnxruntime/core/util/qmath.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/onnxruntime/core/util/qmath.h b/onnxruntime/core/util/qmath.h
index bdaed61b04..055241061f 100644
--- a/onnxruntime/core/util/qmath.h
+++ b/onnxruntime/core/util/qmath.h
@@ -43,9 +43,11 @@ void QGemm(
     concurrency::ThreadPool* thread_pool);
 
 inline float RoundHalfToEven(float input) {
-  std::fesetround(FE_TONEAREST);
-  auto result = std::nearbyintf(input);
-  return result;
+  if (!std::isfinite(input)) {
+    return input;
+  }
+  // std::remainder returns x - n, where n is the integral value nearest to x. When |x - n| = 0.5, n is chosen to be even
+  return input - std::remainderf(input, 1.f);
 }
 
 }  // namespace onnxruntime